The gene-expression micro-array technology allows for rapid and simultaneous determination of expression values for a large number of genes. This technology is used to view the expression level of many genes under different conditions. The data collected through the use of this technology must be managed and presented to the user in such a fashion that "interesting" patterns within the data are revealed. In this project, we propose to develop software methods and tools for visualization of large numbers of gene expression profiles. Our first goal will be the development of algorithms and methods for visualization of gene expression data. This will involve the development of suitable methods for normalizing quantified gene expression values obtained from different experiments, and using different quantification schemes, as well as the visualization of the normalized expression values. Our second goal will be the design and implementation of appropriate database structures for support of gene expression data. We will design databases for optimal performance, evaluate appropriateness of data warehousing vs distributed database structures for suitability on gene expression data, implement database schemas and populate them with gene expression data, and measure performance. Our third goal will be the prototyping and evaluation of Java implementation of the algorithms. We will select a number of visualization tools for implementation using the Java language and a web browser interface.